The present invention relates to electrostatographic reproducing apparatus and more particularly to a mounting assembly for mounting a removable processing cartridge to the main frame of the reproducing apparatus.
In the electrostatographic reproducing apparatus commonly in use today, a photoconductive insulating member is typically charged to uniform potential and thereafter exposed to a light image of an original document to be reproduced. The exposure discharges the photoconductive insulating surface in exposed or background areas and creates an electrostatic latent image on the member which corresponds to the image areas contained within the usual document. Subsequently, the electrostatic latent image on the photoconductive insulating surface is made visible by developing the image with developing powder referred to in the art as toner. Most development systems employ a developer material which comprises both charged carrier particles and charged toner particles which triboelectrically adhere to the carrier particles. During development the toner particles are attracted from the carrier particles by the charge pattern of the image areas in the photoconductive insulating area to form a powder image on the photoconductive area. This image may subsequently be transferred to a support surface such as copy paper to which it may be permanently affixed by heating or by the application of pressure.
In order to minimize maintenance costs by permitting the operator to replace worn out or exhausted processing units in electrostatographic apparatus it has been suggested to incorporate one or more processing units of the apparatus in a disposable or removable cartridge. In this way the operator can readily remove the cartridge when its operational life has been exhausted and insert a new cartridge. Since the replaceable processing unit contains one or more elements which are highly susceptible to damage or deterioration it is important that they be protected prior to and during the replacement operation. For example, if the operator's fingers contact the photoreceptor surface they may deposit grease or oil on the surface which will in some way inhibit the subsequent transfer of toner to paper thereby essentially destroying the functionality of the photoreceptor. In addition certain photoreceptors are highly sensitive to light requiring changing in the dark to avoid unnecessary overexposure. In some way when exposed for extended periods of time the light may have an adverse affect on the overall life of the photoreceptor. Furthermore, without some protection it is possible that the photoreceptor as well as other process units be subjected to the possibility of other physical damage if they are not adequately protected.